OBJECTIVE Determine if the Pillar palatal implant system reduces continuous positive airway pressure (CPAP) pressure and improves patient compliance with CPAP therapy. METHODS Randomized, double-blind, placebo-controlled study. METHODS Four geographically dispersed tertiary sleep disorder referral centers. METHODS Subjects with mild to moderate sleep apnea dissatisfied with CPAP because of pressure-related complaints were randomized to receive Pillar implants or a sham procedure performed in double-blind fashion. Active and sham groups were compared for changes in therapeutic CPAP pressures (primary outcome) with a 90-day follow-up sleep study and CPAP compliance (secondary outcome) with a 90-day smart card report. RESULTS Twenty-six subjects were randomized to Pillar implants and 25 to a sham implant procedure. There were no differences between groups with regard to demographics and baseline parameters. Both sham and active groups had reduced mean CPAP pressure (-1.1 vs -0.5 cm H(2)O) with no difference between groups (P = .32) at 90-day follow-up. In addition, there was no difference in average daily CPAP use between groups (P = .80). Both groups experienced improvements in Epworth sleepiness scores and Functional Outcome of Sleep Questionnaire scores at 90 days with no differences between groups. The active group reported significantly higher CPAP satisfaction scores than the sham group (P = .04). CONCLUSIONS Pillar implants do not significantly reduce CPAP pressure or increase CPAP compliance compared to sham controls but may subjectively improve CPAP satisfaction. These findings do not presently support the use of Pillar implants as an adjunctive treatment to improve CPAP compliance.